Because the course does not start automatically

"Due to the new autoplay policies in some browsers, audio and video on the first slide of a course might not work. To fix this problem, we added a play button to Storyline and Studio courses that have audio or video introductions. By clicking the play button, learners give their browsers permission to play the media...Audio and video content on other slides in your course should play as expected. However, if your slides are set to advance automatically without any interaction, media might not work since learners haven't given their browsers permission to play it."

Storyline and Studio: Media Doesn't Autoplay When Slides Advance Automatically

Thanks Joseph Francis but here is the beginning of the course, it is the load, nor has it entered the menu, the second image is the start menu of the course and thanks for the link.

Because so many people are watching non-work related videos at work, and getting in trouble if a video starts at a high volume, you have this problem. Google (who owns youtube) wants people to have a chance to turn their volume down and not get in trouble, yet keep watching their videos. So they made the browser so the user must interact with a web page (or series of pages) before a video can play, giving the user the opportunity to turn the volume down first. Other browsers followed them, so you can't start a video on your project until the learner has interacted with the web page - usually by clicking something. Not your fault, not Articulate's fault, it's the browser's design.

Well... that is part of it. 😉 Another part is a site (an LMS, for example) which opens a new tab for a course, but doesn't give it focus. If a browser tab does not have focus, the embedded media content is prevented from automatically playing UNTIL the user "gives" it permission to play (by clicking on the PLAY button). Another example would be you would be reading a long article which includes several hyperlinks which you right-click, open in new tab on, only to have the embedded video start playing (if you right-click a hyperlink and select "Open in new tab," the browser maintains focus on your current window. It does not give it to the new window).

Even legitimate sites sometimes intentionally opened additional child windows behind the current parent window using the window.open(); Javascript method. AND, using Flash, have annoying advertising play, which would send you diving for the volume control. I, for one, like that they are stymied from doing that.